Transistor structure with field plate for reducing area thereof

Abstract

In some embodiments, a BJT structure includes a base region, an emitter region formed in the base region and including an emitter doping region, a collector region including a collector doping region, an insulating structure and a field plate. The base region forms a junction with the collector region between the emitter and collector doping regions. The field plate is formed over an insulating structure over the junction. A first distance between the corresponding emitter and collector doping regions to the junction is shorter than a second distance in another BJT structure without the field plate corresponding to the first distance. The first distance causes a breakdown of the junction corresponding to a first breakdown voltage value between the emitter and collector doping regions being substantially the same or greater than a second breakdown voltage value of the other BJT structure corresponding to the first breakdown voltage value.

What is claimed is: 
     
       1. A bipolar junction transistor (BJT) structure, comprising:
 a base region; 
 an emitter region formed in the base region, the emitter region comprising an emitter doping region; 
 a collector region, the collector region comprising a collector doping region; 
 an insulating structure at least a portion of which is interposed between the emitter doping region and the collector doping region; and 
 a field plate formed over the insulating structure and a junction between the collector region and the base region, 
 wherein a width of the field plate spans a first distance between closer substantial end lines of corresponding bottoms of the corresponding emitter doping region and the collector doping region to the junction and the first distance results in breakdown of the junction corresponding to a first breakdown voltage value between the emitter doping region and the collector doping region. 
 
     
     
       2. The BJT structure of  claim 1 , wherein the insulating structure is formed above the emitter doping region and the collector doping region. 
     
     
       3. The BJT structure of  claim 1 , wherein the base region surrounds the collector region. 
     
     
       4. The BJT structure of  claim 1 , wherein
 the base region comprises:
 a first well;
 the emitter region being formed in the first well; 
 
 a second well forming a second junction with the collector region on opposite sides of the junction; and 
 a buried layer under the first well, the second well and the collector region, and connected to the first well and the second well. 
 
 
     
     
       5. The BJT structure of  claim 1 , further comprising:
 at least one another emitter region formed in the base region; 
 another plurality of collector regions;
 the base region forming another plurality of junctions with the other plurality of collector regions; and 
 each junction of the other plurality of junctions being formed between the corresponding emitter doping region of the emitter region and the at least one other emitter region, and the corresponding collector doping region of the other plurality of collector regions; 
 
 another plurality of insulating structures each of which is formed at least partially between the corresponding emitter doping region of the emitter region and the at least one other emitter region and the corresponding collector doping region of the other plurality of collector regions; and 
 another plurality of field plates formed over the corresponding other plurality of insulating structures;
 another plurality of first distances each of which is between a first substantial end line of a first bottom of the corresponding emitter doping region of the emitter region and the at least one other emitter region and a second substantial end line of a second bottom of the corresponding collector doping region of the other plurality of collector regions and results in the first breakdown voltage value;
 the first substantial end line of the first bottom and the second substantial end line of the second bottom for the first distance being closer to the corresponding junction of the plurality of junctions. 
 
 
 
     
     
       6. The BJT structure of  claim 5 , wherein the base region surrounds the emitter region, the at least one other emitter region, the collector region and the other plurality of collector regions. 
     
     
       7. The BJT structure of  claim 1 , wherein the emitter region is p-type, the base region is n-type and the collector region is p-type. 
     
     
       8. The BJT structure of  claim 1 , wherein the insulating structure is over the junction. 
     
     
       9. The BJT structure of  claim 1 , wherein the junction is closer to the emitter region than the collector region. 
     
     
       10. A bipolar junction transistor (BJT) structure, comprising:
 a base region; 
 an emitter region formed in the base region; 
 an emitter contact electrically contacting the emitter region; 
 a collector region; 
 a collector contact electrically contacting the collector region;
 the base region forming a junction with the collector region between the emitter contact and the collector contact; 
 
 an insulating structure formed between the emitter contact and the collector contact; and 
 a field plate formed over the insulating structure and over the junction, the field plate being not exceeding a boundary of the insulating structure from a top view;
 a first distance between closer lateral sides of the corresponding collector contact and the emitter contact to the junction and at a top surface of the collector region resulting in breakdown of the junction corresponding to a first breakdown voltage value between the emitter contact and the collector contact. 
 
 
     
     
       11. The BJT structure of  claim 10 , wherein
 a width of the field plate overlaps with a portion of the first distance. 
 
     
     
       12. The BJT structure of  claim 10 , wherein the insulating structure is below the emitter contact and the collector contact. 
     
     
       13. The BJT structure of  claim 10 , wherein the insulating structure is interposed between the emitter contact and the collector contact. 
     
     
       14. The BJT structure of  claim 10 , wherein the base region surrounds the collector region. 
     
     
       15. The BJT structure of  claim 10 , wherein
 the base region comprises:
 a first well;
 the emitter region being formed in the first well; 
 
 a second well forming a second junction with the collector region on opposite sides of the junction; and 
 a buried layer under the first well, the second well and the collector region, and connected to the first well and the second well. 
 
 
     
     
       16. The BJT structure of  claim 10 , further comprising:
 at least one another emitter regions formed in the base region; 
 at least one another emitter contacts electrically contacting the corresponding at least one other emitter region; 
 another plurality of collector regions; 
 another plurality of collector contacts electrically contacting the corresponding other plurality of collector regions;
 the base region forming another plurality of junctions with the other plurality of collector regions; and 
 each junction of the other plurality of junctions being formed between the corresponding emitter contact of the emitter contact and the at least one other emitter contact, and the corresponding collector contact of the other plurality of collector contacts; 
 
 another plurality of insulating structures each of which is formed between the corresponding emitter contact of the emitter contact and the at least one other emitter contact and the corresponding collector contact of the other plurality of collector contacts; and 
 another plurality of field plates formed over the corresponding other plurality of insulating structures;
 another plurality of first distances each of which is between closer lateral sides of the corresponding emitter contact of the emitter contact and the at least one other emitter contact and the corresponding collector contact of the other plurality of collector contacts to the corresponding junction of the plurality of junctions and results in the first breakdown voltage value. 
 
 
     
     
       17. The BJT structure of  claim 16 , wherein the base region surrounds the emitter region, the at least one other emitter region, the collector region and the other plurality of collector regions. 
     
     
       18. The BJT structure of  claim 10 , wherein the emitter region is p-type, the base region is n-type and the collector region is p-type. 
     
     
       19. A field effect transistor (FET) structure, comprising:
 a body region; 
 a source region formed in the body region; 
 a drift region; 
 a drain region formed in the drift region;
 the drain region being of the same conductivity type as the drift region; 
 the body region forming a junction with the drift region between the source region and the drain region; 
 
 a gate structure extending continuously from the source region to the drain region; 
 a field plate formed over and at least partially overlapped with the gate structure and formed over the junction; and 
 an insulating structure interposed at least between the gate structure and the field plate at where the gate structure and the field plate overlap;
 wherein a portion of a top surface of the gate structure is free from overlapping with the field plate. 
 
 
     
     
       20. The FET structure of  claim 19 , wherein the source region is p-type, the body region is n-type, the drift region is p-type and the drain region is p-type.